Just got back from the dyno this afternoon working on a buddy's car. His is an 87 Turbo II with one of my half-bridgeport setups on a series 4 turbo motor using a Master Power T70 w/ a 1.15 A/R hotside, a Haltech E6K, 720/1680 injector combo, and a Mk4 Toyota Supra fuel pump. This is the 2nd time the car has been to the dyno. Today was over 90 degrees and humid; not a good day to dyno. The schedule was a bit impromptu and we weren't prepared for everything.

We dyno'd the car two months ago and it made 434rwhp at 19-20psi. It did very well in the lower RPM's. The car, however, had a big problem with the exhaust at the time, running a 3" downpipe and midpipe to a 2.5" pipe w/ secondary, "box" muffler. It was producing alot of backpressure. We had it fixed and were going to see what it would do today.

It was making good power; 460's, 470's, and eventually hit 480.8rwhp at 21psi of boost. Problems today:

- Had alot of breakup and shaky up/down power at higher RPM's under load.
- Couldn't get over 22psi although it was mainly sitting around 20-21psi the entire time (I wanted to push it to 25-27psi and stretch that turbo out some)

I believe the break-up was due to old spark plugs. We just forgot to change them out; they've been through one rebuild as well as months and months of driving and tuning. There's no telling what kind of shape they're in. Using BUR9EQ's all around. I'm not sure what was causing the lack of overall boost but I believe it's an air leak somewhere. We haven't tested the blow off valve to see if the spring is too loose. Also, he may be leaking air out on one of the intake manifold gaskets.

The air/fuel ratios were kept at a moderate 12:1 thereabouts under load with race gas, and were steady, so I can't attribute it to the jumps in power. The car felt damn powerful on the way home; a high 10 second 1/4mi slip I think will be possible with it. No problems with shakiness of power or breakup on the road.

Here's a link to the pics and videos:

http://bdc.genxracing.com/Videos/DynoDay_060705

Thanks to Klar for coming out to lend us a 3rd hand with the water sprayer, camera, and Hawk eyes. It was damn hot today!!!!! Hope to break 500's soon.

More to come later ...

B

 

those are some good numbers.. but get a better turbo on that thing you should be well over the 500rwhp mark especially with 21psi area

 

Hey BC,

The thing is leaking air out somewhere.. The boost response on it was horrific today and I'm not sure why. We did have the car apart awhile back so maybe we loused something up when we put it all back together. Granted also, it was 110 degrees inside the shop. That might've had something to do with the figures.

That turbo seems pretty decent so far. It's the Master Power T70 unit that's on eBay alot (not the SSAutochrome trash bin garbage). The compressor wheel is a T70 minor with a T66 major so it moves quite a bit of air.

B

 

Wow amazing numbers.

Care to mention how much advance you were running?

-Jacob

 

damm good numbers!
shoot quite impressed it was done with one of those Master Power Turbo's
wonder how that GT45 would do
I did buy one and it looked pretty nice (GT45)
but I sold it before I got to use it

 

brian,

congratulations on another nice set of numbers.

your ports got a pretty good workout yesterday... seven logged 120 mph 3 and 4th gear pulls on county road B for Bonneville

i am finding the ports need alot of fuel up top. exhaust backpressure solved w the larger hotsides and working on getting my egts under control.

keep it up,

howard coleman

 

very true.. good call.. nice numbers though not bad for that turbo.. and 110Deg is friggin hot! ouch.. what were your intake temps?

 

Very believable (but no less impressive for that).

Well done.

 

Yep it was 110 in the shop... and the dyno is a bit of the ways in the shop where it was so we were baking pretty badly. I think the actual ambient temperature was about 95F or so; I'm not positive.

The intake air temps shot up to about 150F degrees. Eric may need a bit of a larger intercooler, I think.

B

 

shdflgl;sdgjl;skj
This is how I felt after getting home.

We needed bigger fans and a few beers...

I tried finding all the issues I could. In the end I think the boost issues we had were the results of the ignition breakup. Did he go get plugs yet?

I think someone needs better clamps and hose...(nothing but love)

Oh and I have alot of ringing noise in my ears today. I'm ordering some cool ear plugs for next time...

 

481 at the wheels is very impressive to me, which only goes to show what i've known all along: the -RE and -REW blocks, although they may be a little stronger, making ridiculous power with the S4 blocks is still a "real world" reality.

good stuff, BDC!

 

I"M ALL about the beer!!!!! good job BDC

 

This was on Eric's FC I am assuming? Great stuff B, keep it coming

 

Yea, it was on Eric's FC.

 

congrats

 

Hey Brian,

I've been on the "lists" as long as you, and I mean no disrespect, but I saw some funky stuff in those picts.

1) The puke tank for the radiator has an overflow hose that would put any coolan overflow onto the leading coils.... I can't imagine this is a good thing.

2) I understand that the water spray was for the high temps and the dyno... what happens, however, when you tune around water spray on the intercooler, and then go driving through Texas heat which can and does get over 100 degrees, and you have no water cooling available?

Beyond those two issues, it all looks copesetic. By the way, what size Intercooler is that? It does indeed look too small for the application. Starion? NPR?

Nice work on the HP numbers, to be sure!

Collin Webster
89 TII

 

Ah, ok. I'll respond to this...since it is my car.

1) the overflow is a temporary "bandaid". this is car in no means perfect. Also its only spilled out once. I probably need to put the other one on.

2) The water sprayer is to combat high temps since when on the dyno, the car isnt in motion ie; 70-90mph..thus it isnt recieving its normal cooling.

Also the intercooler is an RE Amemiya old school kit, i think made by GReddy.

ERic.

 

Hey Collin,

1) Hah! I didn't notice that. Good eye.

2) That's a good point, as well. I didn't personally see a dramatic change in temperatures while on the road vs. sitting on the dyno w/ the spray, but you've also got to remember that the vehicle, when running on the highway, will be getting a heck of alot more air forced through the heat exchangers than it would with it sitting on the dyno w/ a dinky fan blowing on it.

The IC is the older-style GReddy unit.

Thanks!

B

 

You're the man B...I'm still trying to figure out a way to get you down here

 

Well, I'm glad I wasn't totally off base, because you've forgotten more about rotaries than I'll ever learn. I still think about your comments when I fire up my hybrid turbo that the exhaust wheel is too small... so far, however, so good!

Keep up the work with the killer HP, it's important for the other RX-7's to see the FC can still put it down!

Collin Webster
89 TII